JP7280663B2 - holding device - Google Patents

Description

The technology disclosed in this specification relates to a holding device that holds an object.

For example, an electrostatic chuck is used as a holding device for holding a wafer when manufacturing semiconductors. The electrostatic chuck comprises: a ceramic member having a substantially planar surface (hereinafter referred to as "adsorption surface") substantially perpendicular to a predetermined direction (hereinafter referred to as "first direction"); and a ceramic member provided inside the ceramic member. The wafer is attracted to and held by the attraction surface of the ceramic member using electrostatic attraction generated by applying a voltage to the chuck electrode.

If the temperature of the wafer held on the attraction surface of the electrostatic chuck does not reach the desired temperature, the precision of each process (film formation, etching, etc.) on the wafer may decrease. The ability to control the distribution is required. Therefore, for example, a plurality of heater electrodes are provided inside the ceramic member. When a voltage is applied to each heater electrode, each heater electrode generates heat to heat the ceramic member, thereby controlling the temperature distribution of the attracting surface of the ceramic member (and thus the temperature of the wafer held by the attracting surface). distribution control) is realized.

Since each heater electrode is electrically connected to the power supply terminal through the driver electrode, the amount of heat generated in the current path portion of the driver electrode (the path through which the current supplied to the heater electrode flows) is greater than the portion other than the current path portion. It can grow. In such a case, since the temperature of the current path portion of the driver electrode is higher than that of the portion other than the current path portion, it is necessary to control the temperature distribution of the attraction surface of the ceramic member (and thus the temperature distribution of the wafer held by the attraction surface). control). In order to suppress heat generation in the current path portion, a configuration is sometimes adopted in which the thickness of the current path portion is thicker than the portion other than the current path portion (see, for example, Patent Document 1).

JP 2015-191837 A

A configuration in which the plurality of heater electrodes are connected in parallel to the driver electrodes may be adopted. In such a configuration, there may be a portion where the above-described current path portions corresponding to the heater electrodes overlap each other (hereinafter referred to as "overlapping portion"). In that case, the amount of current flowing in the overlapping portion is greater than that in the non-overlapping portion (hereinafter also referred to as “non-overlapping portion”) of the current path portion, so the amount of heat generated in the overlapping portion is the same as the non-overlapping portion. part, and the overlapping part can become a hot temperature singularity. However, in the driver electrode, only with the above-described conventional configuration in which the thickness of the current path portion is thicker than the thickness of the non-overlapping portion, it is possible to suppress the overlapping portion of the current path portion from becoming a high temperature singular point. can't Therefore, in the conventional electrostatic chuck, there is room for improvement in terms of controllability of the temperature distribution of the attracting surface of the ceramic member (and thus controllability of the temperature distribution of the wafer).

Such a problem is not limited to electrostatic chucks that use electrostatic attraction to hold a wafer, but is common to all holding devices that include a ceramic member and hold an object on the surface of the ceramic member. .

This specification discloses a technology capable of solving the above-described problems.

The technology disclosed in this specification can be implemented, for example, in the following forms.

(1) A holding device disclosed in this specification includes a ceramic member having a substantially planar first surface substantially perpendicular to a first direction, and a linear first surface disposed inside the ceramic member. a heater electrode and a second heater electrode; a first power supply terminal; and one end of the first heater electrode and one end of the second heater electrode disposed inside the ceramic member. and a driver electrode electrically connected to the first power supply terminal, the holding device holding an object on the first surface of the ceramic member, wherein the driver electrode is connected to the first a first power supply portion electrically connected to the power supply terminal of the first heater electrode; a first connection portion electrically connected to the one end of the first heater electrode; a second connection portion located between the first connection portion and electrically connected to the one end of the second heater electrode; a first current path portion between a connecting portion and a second current path portion between the first feeding portion and the second connecting portion, wherein the second current path The portion has an overlapping portion that overlaps with the first current path portion when viewed in the first direction, and the first power supply is supplied from the second connecting portion in the overlapping portion of the second current path portion. The area of the cross section of the overlapping portion of the second current path portion substantially perpendicular to the direction toward the portion is the area between the first connection portion and the second connection portion of the first current path portion. is larger than the area of the cross section of the first current path portion substantially perpendicular to the direction from the first connecting portion to the first feeding portion. According to this holding device, in the configuration in which the first heater electrode and the second heater electrode are electrically connected in parallel, the driver electrode is the first power supply portion electrically connected to the first power supply terminal. , a first connecting portion electrically connected to the end of the first heater electrode, and a second connecting portion electrically connected to the end of the second heater electrode. Also, in the driver electrode, the second connection portion is positioned between the first power supply portion and the first connection portion. Further, the driver electrode has a first current path portion between the first feed portion and the first connection portion and a second current path portion between the first feed portion and the second connection portion. and The second current path portion has an overlapping portion that overlaps the first current path portion when viewed from the first direction. In such a configuration, the amount of current flowing through the overlapping portion of the second current path portion is equal to the amount of current flowing through the region between the first connection portion and the second connection portion in the first current path portion. The overlapping portion of the second current path portion in the driver electrode is likely to be a high-temperature temperature singularity. However, as described above, in the present holding device, in the overlapping portion of the second current path portion, the overlapping portion of the second current path portion substantially orthogonal to the direction from the second connecting portion to the first feeding portion is substantially perpendicular to the direction from the first connecting portion to the first feeding portion in the region between the first connecting portion and the second connecting portion in the first current path portion larger than the cross-sectional area of the first current path portion. Therefore, it is possible to reduce the electrical resistance in the overlapping portion of the second current path portion, which is the portion where the amount of flowing current is large, and thereby suppress the occurrence of a high-temperature temperature singular point.

(2) In the above holding device, the cross-sectional thickness of the overlapping portion of the second current path portion in the first direction may be thicker than the cross-sectional thickness of the first current path portion. good. By adopting such a configuration, in the present holding device, the electrical resistance in the overlapping portion of the second current path portion, which is likely to become a high-temperature singular point due to the large amount of current flowing in the driver electrode, is reduced. In addition, the occurrence of a high-temperature temperature singularity can be suppressed.

(3) In the holding device, in the first current path portion, there is a step between the overlapping portion of the second current path portion and a portion of the second current path portion other than the overlapping portion. It is good also as a structure provided with the part. By adopting such a configuration, in the present holding device, the temperature unevenness in the overlapping portion of the second current path portion and the temperature unevenness in the non-overlapping portion of the first current path portion can be reduced. can be mitigated.

(4) The holding device further includes a linear third heater electrode disposed inside the ceramic member, wherein the driver electrode is connected to the first connection portion by the second connection portion. and a third connecting portion electrically connected to one end of the third heater electrode, and a third connecting portion between the first feeding portion and the third connecting portion. 3 current path portions, wherein the third current path portion has an overlapping portion that overlaps with the first current path portion when viewed in the first direction, and the third current path portion substantially perpendicular to the direction from the first connecting portion to the first feeding portion in the region between the first connecting portion and the second connecting portion in the overlapping portion of The area of the cross section of the overlapping portion of the current path portion is from the third connection portion in the region between the first connection portion and the third connection portion in the third current path portion A configuration may be adopted in which the area of the cross section of the third current path portion that is substantially perpendicular to the direction toward the first power feeding portion is larger than that of the cross section. According to this holding device, in the configuration in which the first heater electrode, the second heater electrode, and the third heater electrode are electrically connected in parallel, the driver electrode is further provided at one end of the third heater electrode. and a third connecting portion electrically connected to the . Also, in the driver electrode, the third connection portion is located on the opposite side of the second connection portion with respect to the first connection portion. Further, the driver electrode includes a third current path portion between the first feeding portion and the third connection portion, the third current path portion being the same as the first current path when viewed in the first direction. It has an overlapping portion that overlaps the portion. In such a configuration, the amount of current flowing through the region between the first connection portion and the second connection portion in the overlapping portion of the third current path portion is the same as that of the first current path portion in the third current path portion. The amount of current flowing in the region between the connection portion and the third connection portion is large compared to the amount of current flowing between the first connection portion and the second connection portion in the overlapping portion of the third current path portion in the driver electrode. is likely to be a temperature singular point of higher temperature than the region between the first connection portion and the third connection portion in the third current path portion. In this holding device, in the region between the first connecting portion and the second connecting portion in the overlapped portion of the third current path portion, there is substantially a direction from the first connecting portion toward the first feeding portion. The area of the cross section of the overlapping portion of the third current path portion orthogonal to each other is from the third connection portion to the third connection portion in the region between the first connection portion and the third connection portion of the third current path portion. It is larger than the area of the cross section of the third current path portion which is substantially perpendicular to the direction toward the first feeding portion. Therefore, the electric resistance in the region between the first connection portion and the second connection portion in the overlapping portion of the third current path portion, which is a portion where the amount of current flowing is large, is reduced, and thus the high-temperature It is possible to suppress the occurrence of temperature singularities.

(5) A holding device disclosed in this specification includes a ceramic member having a substantially planar first surface substantially perpendicular to a first direction, and a linear first surface disposed inside the ceramic member. a heater electrode and a second heater electrode; a first power supply terminal and a second power supply terminal; A holding device for holding an object on the first surface of the ceramic member, the holding device comprising a driver electrode electrically connected to one end of the electrode and the first power supply terminal, wherein the driver The electrode includes: a first power supply portion electrically connected to the first power supply terminal; a first connection portion electrically connected to the one end of the first heater electrode; a second connection portion located between the first power supply portion and the first connection portion and electrically connected to the one end of the second heater electrode; and the first power supply. a first current path portion between the portion and the first connecting portion; and a second current path portion between the first feeding portion and the second connecting portion; The second current path portion has an overlapping portion that overlaps with the first current path portion when viewed in the first direction, and the second connection portion in the overlapping portion of the second current path portion The thickness of the cross-section of the overlapping portion of the second current path portion substantially perpendicular to the direction from the second current path portion to the first power supply portion is the thickness of the first connection portion and the first connection portion of the first current path portion. It is thicker than the cross-sectional thickness of the first current path portion substantially perpendicular to the direction from the first connection portion to the first power supply portion in the region between the two connection portions. According to this holding device, in the configuration in which the first heater electrode and the second heater electrode are electrically connected in parallel, the driver electrode is the first power supply portion electrically connected to the first power supply terminal. and first and second connection portions electrically connected to respective one ends of the first and second heater electrodes. Also, in the driver electrode, the second connection portion is positioned between the first power supply portion and the first connection portion. Further, the driver electrode has a first current path portion between the first feed portion and the first connection portion and a second current path portion between the first feed portion and the second connection portion. and The second current path portion has an overlapping portion that overlaps the first current path portion when viewed from the first direction. In such a configuration, the amount of current flowing through the overlapping portion of the second current path portion is equal to the amount of current flowing through the region between the first connection portion and the second connection portion in the first current path portion. The overlapping portion of the second current path portion in the driver electrode is likely to be a high-temperature temperature singularity. In the present holding device, the cross-sectional thickness of the overlapping portion of the second current path portion, which is substantially perpendicular to the direction from the second connection portion to the first feeding portion, in the overlapping portion of the second current path portion is A first current path portion substantially perpendicular to a direction from the first connection portion to the first feeding portion in a region between the first connection portion and the second connection portion of the one current path portion By making it thicker than the thickness of the cross section, it is possible to reduce the electrical resistance in the overlapping portion of the second current path portion, which is the portion where the amount of current flowing is large, and thereby suppress the occurrence of a high temperature singular point.

The technology disclosed in this specification can be implemented in various forms, for example, holding devices, electrostatic chucks, heater devices such as CVD heaters, vacuum chucks, manufacturing methods thereof, and the like. It is possible to realize by

1 is a perspective view schematically showing an external configuration of an electrostatic chuck 100 according to this embodiment; FIG. It is an explanatory view showing roughly the XZ section composition of electrostatic chuck 100 in this embodiment. It is an explanatory view showing roughly the XY section composition of electrostatic zipper 100 in this embodiment. It is an explanatory view showing roughly the XY section composition of electrostatic zipper 100 in this embodiment. FIG. 4 is an explanatory diagram showing the positional relationship between a first heater-side via 721 and a first feeder-side via 711 in a first driver electrode 60x of the electrostatic chuck 100 of this embodiment; FIG. 4 is an explanatory diagram showing a current path portion in the first driver electrode 60x of the electrostatic chuck 100 of this embodiment; It is an explanatory diagram showing the positional relationship between the first heater-side via 721 and the first feeder-side via 711 in the first driver electrode 60x of the electrostatic chuck 100 of the present embodiment and the XZ cross-sectional configuration of the first driver electrode 60x. be. FIG. 11 is an explanatory diagram showing the positional relationship between a first heater-side via 721 and a first power supply-side via 711 in a first driver electrode 60x of a modified electrostatic chuck 100; FIG. 11 is an explanatory diagram showing a current path portion in the first driver electrode 60x of the electrostatic chuck 100 of the modified example;

A. Embodiment:
A-1. Configuration of electrostatic chuck 100:
FIG. 1 is a perspective view schematically showing the external configuration of an electrostatic chuck 100 according to the present embodiment, and FIG. 2 is an explanatory view schematically showing the XZ cross-sectional configuration of the electrostatic chuck 100 according to the present embodiment. , 3 and 4 are explanatory diagrams schematically showing the XY cross-sectional configuration of the electrostatic chuck 100 in this embodiment. 2 shows the XZ cross-sectional configuration of electrostatic chuck 100 at position II-II in FIGS. 3 and 4, and FIG. 3 shows electrostatic chuck 100 at position III-III in FIG. An XY cross-sectional configuration is shown, and FIG. 4 shows an XY cross-sectional configuration of the electrostatic chuck 100 at the position IV-IV in FIG. Each figure shows mutually orthogonal XYZ axes for specifying directions. In this specification, for the sake of convenience, the positive direction of the Z-axis is referred to as the upward direction, and the negative direction of the Z-axis is referred to as the downward direction. may be

The electrostatic chuck 100 is a device that attracts and holds an object (for example, a wafer W) by electrostatic attraction, and is used, for example, to fix the wafer W within a vacuum chamber of a semiconductor manufacturing apparatus. The electrostatic chuck 100 includes a ceramic member 10 and a base member 20 arranged side by side in a predetermined arrangement direction (vertical direction (Z-axis direction) in this embodiment). The ceramic member 10 and the base member 20 are arranged such that the lower surface S2 (see FIG. 2) of the ceramic member 10 and the upper surface S3 of the base member 20 face each other in the arrangement direction.

The ceramic member 10 is a plate-shaped member having a substantially circular planar upper surface (hereinafter referred to as “adsorption surface”) S1 substantially orthogonal to the arrangement direction (Z-axis direction) described above, and is made of ceramics (for example, alumina or aluminum nitride). etc.). The diameter of the ceramic member 10 is, for example, about 50 mm to 500 mm (usually about 200 mm to 350 mm), and the thickness of the ceramic member 10 is, for example, about 1 mm to 10 mm. The adsorption surface S1 of the ceramic member 10 corresponds to the first surface in the claims, and the Z-axis direction corresponds to the first direction in the claims. Also, in this specification, a direction perpendicular to the Z-axis direction is referred to as a "plane direction".

As shown in FIG. 2, a chuck electrode 40 made of a conductive material (eg, tungsten, molybdenum, platinum, etc.) is arranged inside the ceramic member 10 . The shape of the chuck electrode 40 as viewed in the Z-axis direction is, for example, a substantially circular shape. When a voltage is applied to the chuck electrode 40 from a power supply (not shown), electrostatic attraction is generated, and the wafer W is attracted and fixed to the attraction surface S1 of the ceramic member 10 by this electrostatic attraction.

Inside the ceramic member 10, a heater electrode layer 50 for controlling the temperature distribution of the attraction surface S1 of the ceramic member 10 (that is, controlling the temperature distribution of the wafer W held on the attraction surface S1) and a heater electrode layer 50 are arranged. These configurations will be described in detail later.

The base member 20 is, for example, a circular planar plate member having the same diameter as the ceramic member 10 or having a larger diameter than the ceramic member 10, and is made of metal (aluminum, aluminum alloy, etc.), for example. The diameter of the base member 20 is, for example, approximately 220 mm to 550 mm (usually 220 mm to 350 mm), and the thickness of the base member 20 is, for example, approximately 20 mm to 40 mm.

The base member 20 is joined to the ceramic member 10 by a joining portion 30 arranged between the lower surface S2 of the ceramic member 10 and the upper surface S3 of the base member 20. As shown in FIG. The joint portion 30 is made of an adhesive such as silicone resin, acrylic resin, or epoxy resin. The thickness of the joint portion 30 is, for example, about 0.1 mm to 1 mm. Note that the joint portion 30 may be arranged on the entire lower surface S2 of the ceramic member 10, or may be arranged only on a part of the lower surface S2.

A coolant channel 21 is formed inside the base member 20 . When a coolant (for example, a fluorine-based inert liquid, water, or the like) is caused to flow through the coolant channel 21 , the base member 20 is cooled, and heat transfer ( The ceramic member 10 is cooled by the thermal drawing, and the wafer W held on the adsorption surface S1 of the ceramic member 10 is cooled. Thereby, control of the temperature distribution of the wafer W is realized.

A-2. Configuration of heater electrode layer 50 and the like:
Next, the configuration of the heater electrode layer 50 and the configuration for power supply to the heater electrode layer 50 will be described in detail. As described above, the electrostatic chuck 100 includes the heater electrode layer 50 between the chuck electrode 40 and the lower surface S2 of the ceramic member 10 (see FIG. 2). The heater electrode layer 50 is made of a conductive material (eg, tungsten, molybdenum, platinum, etc.).

As shown in FIG. 4, the heater electrode layer 50 includes multiple heater electrodes 500 . Note that FIG. 4 shows only three heater electrodes among the plurality of heater electrodes 500 provided in the electrostatic chuck 100, and the other heater electrodes 500 are omitted. These three heater electrodes 500 are hereinafter referred to as a first heater electrode 500a, a second heater electrode 500b and a third heater electrode 500c, respectively.

Each heater electrode 500 has a heater line portion 510 and a heater pad portion (a first heater pad portion 521 and a second heater pad portion 522). The heater line portion 510 is a linear resistance heating element extending in a substantially circular or substantially spiral shape when viewed in the Z-axis direction. The first heater pad portion 521 and the second heater pad portion 522 are connected to both ends of the heater line portion 510, respectively. The shape of the first heater pad portion 521 and the second heater pad portion 522 is, for example, substantially circular when viewed in the Z-axis direction. The width of the first heater pad portion 521 and the second heater pad portion 522 is larger than the width of the heater line portion 510 when viewed in the Z-axis direction. Here, the width of the heater line portion 510 is the width in the direction substantially perpendicular to the axis of the heater line portion 510, and the width of the heater pad portions 521 and 522 is substantially perpendicular to the extension of the axis of the heater line portion 510. width in the direction (see FIG. 4 described later).

In addition, as shown in FIG. 2 , the electrostatic chuck 100 has a configuration for supplying power to each heater electrode 500 forming the heater electrode layer 50 . Specifically, the electrostatic chuck 100 includes a first power supply terminal 741, a first electrode pad 731, a first power supply side via 711, a driver electrode 60, a first heater side via 721, a second heater side A via 722 , a second power supply side via 712 , a second electrode pad 732 and a second power supply terminal 742 are provided.

The driver electrode 60 is formed in a predetermined region parallel to the surface direction between the heater electrode layer 50 and the lower surface S2 of the ceramic member 10, as shown in FIG. Specifically, the electrostatic chuck 100 of the present embodiment includes eight driver electrodes 60, and the eight driver electrodes 60 are arranged in eight directions with respect to the center of the ceramic member 10 as viewed in the Z-axis direction. It is formed in a region divided into two substantially fan shapes. Driver electrode 60 is made of a conductive material (eg, tungsten, molybdenum, platinum, etc.).

In the present embodiment, among the eight driver electrodes 60, the first heater electrode 500a, the second heater electrode 500b and the third heater electrode 500c are connected to the first driver electrode 60x and the second driver electrode 60y. are electrically connected in parallel. Specifically, the first heater electrode 500a will be described. Bonded to the ends. The other end of the first heater-side via 721a is joined to the first driver electrode 60x. Similarly, the second heater pad portion 522a of the first heater electrode 500a is joined to one end of the second heater-side via 722a. The other end of the second heater-side via 722a is joined to the second driver electrode 60y. Also, the heater-side vias 721a and 722a are made of a conductive material. Each of the heater-side vias 721a and 722a is composed of a plurality of vias (four in this embodiment) (see FIG. 5 described later). Since the second heater electrode 500b and the third heater electrode 500c are also similar to the first heater electrode 500a, description thereof is omitted.

Further, as shown in FIG. 2, the electrostatic chuck 100 is formed with a first terminal hole 110 and a second terminal hole 120 extending from the lower surface S4 of the base member 20 to the inside of the ceramic member 10. . The first terminal hole 110 and the second terminal hole 120 are a through hole 22 vertically penetrating the base member 20 , a through hole 32 vertically penetrating the joint portion 30 , and the lower surface of the ceramic member 10 . The concave portion 12 formed on the S2 side is an integrated hole formed by communicating with each other.

A columnar first feed terminal 741 is accommodated in the first terminal hole 110 . A first electrode pad 731 is provided on the bottom surface of the recess 12 of the ceramic member 10 forming the first terminal hole 110 . The first power supply terminal 741 is joined to the first electrode pad 731 . Also, the first electrode pad 731 is joined to one end of the first feed-side via 711 . The other end of the first feed-side via 711 is joined to the first driver electrode 60x. Similarly, a columnar second feed terminal 742 is accommodated in the second terminal hole 120 . A second electrode pad 732 is provided on the bottom surface of the concave portion 12 of the ceramic member 10 forming the second terminal hole 120 . The second power supply terminal 742 is joined to the second electrode pad 732 . Also, the second electrode pad 732 is joined to one end of the second feed-side via 712 . The other end of the second feed-side via 712 is joined to the second driver electrode 60y. Also, the power supply terminals 741 and 742, the electrode pads 731 and 732, and the power supply side vias 711 and 712 are made of a conductive material. The shape of the first electrode pad 731 and the second electrode pad 732 is, for example, substantially circular when viewed in the Z-axis direction. Also, each of the first power supply side via 711 and the second power supply side via 712 is composed of a plurality of (four in this embodiment) vias (see FIG. 5 described later).

The first power supply terminal 741 is electrically connected to the first driver electrode 60 x through the first electrode pad 731 and the first power supply side via 711 . The second power supply terminal 742 is electrically connected to the second driver electrode 60 y through the second electrode pad 732 and the second power supply side via 712 . The first heater electrode 500a is electrically connected to the first driver electrode 60x through the first heater-side via 721a and the first heater pad portion 521a, and is electrically connected to the second heater-side via 722a and the first heater pad portion 521a. It is electrically connected to the second driver electrode 60y through the second heater pad portion 522a. The second heater electrode 500b is electrically connected to the first driver electrode 60x through the first heater-side via 721b and the first heater pad portion 521b, and is electrically connected to the second heater-side via 722b and the first heater pad portion 521b. It is electrically connected to the second driver electrode 60y through the second heater pad portion 522b. The third heater electrode 500c is electrically connected to the first driver electrode 60x through the first heater-side via 721c and the first heater pad portion 521c, and is also electrically connected to the second heater-side via 722c and the first heater pad portion 521c. It is electrically connected to the second driver electrode 60y through the second heater pad portion 522c. Thus, the first heater electrode 500a, the second heater electrode 500b, and the third heater electrode 500c are electrically connected in parallel to the first power supply terminal 741 and the second power supply terminal 742. ing. In such a configuration, when the first power supply terminal 741 and the second power supply terminal 742 are connected to a power supply (not shown), the voltage from the power supply is applied to the first heater electrode 500a and the second heater electrode 500a. It is applied to electrode 500b and third heater electrode 500c. When a voltage is applied to the first heater electrode 500a, the second heater electrode 500b and the third heater electrode 500c, the first heater electrode 500a, the second heater electrode 500b and the third heater electrode 500c generate heat. As a result, the ceramic member 10 is heated, thereby controlling the temperature distribution of the attracting surface S1 of the ceramic member 10 (that is, controlling the temperature distribution of the wafer W held on the attracting surface S1).

A-3. Detailed configuration of the first driver electrode 60x:
Next, the detailed configuration of the first driver electrode 60x will be described in detail. As described above, the first driver electrode 60x is fan-shaped when viewed in the Z-axis direction (see FIG. 3).

FIG. 5 is an explanatory diagram showing the positional relationship between the three first heater-side vias 721 and the first power supply-side vias 711 in the first driver electrode 60x of the electrostatic chuck 100 of this embodiment. FIG. 6 is an explanatory diagram showing a current path portion in the first driver electrode 60x of the electrostatic chuck 100 of this embodiment. FIG. 7 shows the positional relationship between the first heater-side via 721 and the first feeder-side via 711 in the first driver electrode 60x of the electrostatic chuck 100 of this embodiment and the XZ cross-sectional configuration of the first driver electrode 60x. It is an explanatory diagram showing. Note that the three first heater-side vias 721 are hereinafter also referred to as a first heater-side via 721a, a first heater-side via 721b, and a first heater-side via 721c, respectively.

A-3-1. Detailed description of first feeding portion 812, first connecting portion 821a, etc.:
As shown in FIG. 5, the first driver electrode 60x includes a first feeding portion 812, a first connecting portion 821a, a second connecting portion 821b and a third connecting portion 821c. . The first power supply portion 812 is electrically connected to the first power supply terminal 741 through the first power supply side via 711 . The first power supply portion 812 is a portion of the first driver electrode 60x that includes all of the plurality of first power supply side vias 711 when viewed in the Z-axis direction. This is the portion surrounded by the outer circumference circle of the first electrode pad 731 when viewed. The first connecting portion 821a is electrically connected to the first heater pad portion 521a, which is one end of the first heater electrode 500a, through a first heater-side via 721a. The first connection portion 821a is a portion of the first driver electrode 60x that includes all of the plurality of heater-side vias 721a when viewed in the Z-axis direction. This is the portion surrounded by the outer circumference circle of the first heater pad portion 521a. The second connection portion 821b is located between the first power feeding portion 812 and the first connection portion 821a, and is connected to one end of the second heater electrode 500b through the first heater-side via 721b. It is electrically connected to a certain first heater pad portion 521b. The second connection portion 821b is a portion of the first driver electrode 60x that includes all of the plurality of first heater-side vias 721b when viewed in the Z-axis direction. This is the portion surrounded by the outer circumference circle of the first heater pad portion 521b. The third connection portion 821c is located on the side opposite to the second connection portion 821b with respect to the first connection portion 821a, and is connected to one end of the third heater electrode 500c through the first heater-side via 721c. is electrically connected to the first heater pad portion 521c. The third connection portion 821c is a portion of the first driver electrode 60x that includes all of the plurality of first heater-side vias 721c when viewed in the Z-axis direction. This is the portion surrounded by the outer circumference circle of the first heater pad portion 521c. In this embodiment, the first feeding portion 812, the first connecting portion 821a, the second connecting portion 821b, and the third connecting portion 821c are positioned on the same straight line. In the following description, the second connecting portion 821b located closest to the first feeding portion 812 will be referred to as the “closest connecting portion 821b”, and the third connecting portion 821c located farthest from the first feeding portion 812 will be referred to as the “most recent connecting portion 821b”. The first connecting portion 821a located between the nearest connecting portion 821b and the farthest connecting portion 821c is also referred to as the "middle connecting portion 821a". In this embodiment, since the first electrode pad 731 and the first heater pad portions 521a, 521b, 521c are substantially circular with the same diameter, the first power supply portion 812 and the connection portions 821a, 821b , 821c are also substantially circular with the same diameter.

A-3-2. Detailed description of first current path portion Ra and overlapping portion Rab, etc.:
As shown in FIGS. 5 and 6, the first driver electrode 60x includes a first current path portion Ra, a second current path portion Rb and a third current path portion Rc. The first current path portion Ra is a portion through which a current flows between the first feeding portion 812 and the intermediate connection portion 821a. The second current path portion Rb is a portion through which a current flows between the first feeding portion 812 and the nearest connection portion 821b. The third current path portion Rc is a portion through which a current flows between the first feeding portion 812 and the farthest connecting portion 821c. In this embodiment, the first current path portion Ra is a belt-like portion including the first power supply portion 812, the intermediate connection portion 821a, and between them. As noted above, the first feed portion 812 and the intermediate connecting portion 821a are of the same diameter. Therefore, the width in the lateral direction in the first current path portion Ra is substantially the same over the entire length. Such a first current path portion Ra can be defined as follows. First, with respect to the intermediate connection portion 821a and the first feed portion 812, two tangent lines TL to both the outer circumference of the intermediate connection portion 821a and the outer circumference of the first feed portion 812 are defined (see A in FIG. 6). reference). In this case, the first current path portion Ra is a portion surrounded by the two tangent lines TL, the outer circumference of the intermediate connection portion 821a, and the outer circumference of the first feeding portion 812. It can be defined as the portion formed by the portion including one feed portion 812 (see FIG. 6A). Further, the second current path portion Rb and the third current path portion Rc are also belt-shaped portions like the first current path portion Ra, and are similar to the second current path portion Rb and the third current path portion Rc. The width in the short direction in Rc is substantially the same over the entire length. The second current path portion Rb (see B in FIG. 6) and the third current path portion Rc (see D in FIG. 6) can also be defined in the same manner as the first current path portion Ra. omitted.

The second current path portion Rb has an overlapping portion Rab that overlaps the first current path portion Ra when viewed in the Z-axis direction, and the third current path portion Rc is the first current path portion when viewed in the Z-axis direction. It has an overlapping portion Rac that overlaps with Ra. In this embodiment, as described above, the first feeding portion 812 and the connecting portions 821a, 821b, 821c are positioned on the same straight line and have the same width in the lateral direction. Therefore, since all portions of the second current path portion Rb overlap the first current path portion Ra, the overlapping portion Rab becomes the same portion as the second current path portion Rb (see C in FIG. 6). ). Further, since all portions of the first current path portion Ra overlap with the third current path portion Rc, the overlapping portion Rac is the same portion as the first current path portion Ra (see E in FIG. 6). ).

The tangent lines SL1, SL2, SL3 and SL4 and the areas A1, A2 and A3 shown in FIGS. 5 and 7 will be described. As described above, in this embodiment, the first feeding portion 812 and the connection portions 821a, 821b, 821c are positioned on the same straight line. Therefore, the tangential lines SL1, SL2, SL3, and SL4 are straight lines parallel to each other and perpendicular to the direction in which the farthest connection portion 821c and the first feeding portion 812 are arranged (the X-axis direction). Specifically, the tangent line SL1 is a tangent line in contact with the farthest point of the farthest connection portion 821c from the intermediate connection portion 821a. The tangent line SL2 is a tangent line that touches the farthest point of the intermediate connection portion 821a from the closest connection portion 821b. A tangent line SL3 is a tangent line that is in contact with the farthest point from the first feeding portion 812 in the nearest connection portion 821b. A tangent line SL4 is a tangent line that is in contact with a point of the first feeding portion 812 that is closest to the nearest connection portion 821b. An area A1 is an area between the intermediate connection portion 821a and the closest connection portion 821b, specifically, an area separated by the tangent lines SL2 and SL3 and including the intermediate connection portion 821a. An area A2 is an area between the nearest connection portion 821b and the first feeding portion 812, specifically, an area separated by a tangent line SL3 and a tangent line SL4 and including the nearest connection portion 821b. . An area A3 is an area between the closest connection portion 821b and the first feeding portion 812, specifically, an area separated by the tangent line SL1 and the tangent line SL2 and including the closest connection portion 821b. .

A-3-3. Detailed description of the cross section Xa of the first current path portion Ra, etc.:
As shown in FIGS. 5, 6 and 7, the cross section Xa of the first current path portion Ra extends from the intermediate connection portion 821a to the first feeding portion 812 in the area A1 of the first current path portion Ra. is a cross section substantially orthogonal to the direction toward . The cross section Xa of the overlapping portion Rac is the same as the cross section Xa of the first current path portion Ra because the overlapping portion Rac is the same portion as the first current path portion Ra, as described above. A cross-section Xc of the third current path portion Rc is a cross-section substantially orthogonal to the direction from the farthest connection portion 821c to the first feeding portion 812 in the region A3 of the third current path portion Rc. A cross section Xb of the overlapping portion Rab is a cross section substantially orthogonal to the direction from the nearest connecting portion 821b toward the first feeding portion 812 in the overlapping portion Rab. The cross section Xb of the overlapping portion Rab is the same as the cross section Xb of the second current path portion Rb because the overlapping portion Rab is the same portion as the second current path portion Rb, as described above. In the first driver electrode 60x of the present embodiment, the area of the cross section Xb of the second current path portion Rb (overlapping portion Rab) is the first current path portion in the region A1 of the first current path portion Ra. Ra (overlapping portion Rac) is larger than the area of the cross section Xa. In addition, in the first driver electrode 60x of the present embodiment, the area of the cross section Xa of the first current path portion Ra (overlapping portion Rac) in the region A1 is the third current path portion Rc in the region A3. 3 larger than the area of the cross section Xc of the current path portion Rc. As described above, in this embodiment, the widths in the short direction of the current path portions Ra, Rb, and Rc are substantially the same over the entire length when viewed in the Z-axis direction. Therefore, the thicknesses of the current path portions Ra, Rb, and Rc in the Z-axis direction are different from each other. That is, in the present embodiment, the thickness Ta of the cross section Xa of the first current path portion Ra (overlapping portion Rac) of the region A1 is 100% with respect to the thickness Tc of the cross section Xc of the third current path portion Rc of the region A3. It is the thickness obtained by adding the thickness Tc of Xc. In addition, the thickness Tb of the second current path portion Rb (overlapping portion Rab) of the region A2 at the cross section Xb is the thickness Ta of the cross section Xa of the first current path portion Ra (overlapping portion Rac) of the region A1. It is the thickness obtained by adding the thickness Tc of the cross section Xc of the third current path portion Rc of A3. The thickness is uniform in each of the regions A1, A2, and A3. Note that the cross section Xa of the first current path portion Ra (overlapping portion Rac) is the cross section of the first current path portion Ra at the center position in the longitudinal direction of the first current path portion Ra in the region A1. . Cross section Xb of overlapping portion Rab is a cross section of second current path portion Rb at the center position in the longitudinal direction of second current path portion Rb in region A2. A cross-section Xc of the third current path portion Rc is a cross-section at the longitudinal center position of the third current path portion Rc in the region A3.

As shown in FIGS. 5 and 7, in the first driver electrode 60x of the present embodiment, a stepped portion 900a is formed between the overlapping portion Rab and portions other than the overlapping portion Rab in the first current path portion Ra. A step portion 900b is provided between the overlapping portion Rac and a portion other than the overlapping portion Rac in the third current path portion Rc. That is, while the surface of the first driver electrode 60x on the side of the attraction surface S1 is flush with the Z-axis direction, the surface of the first driver electrode 60x opposite to the attraction surface S1 is flat in the Z-axis direction. , area A3, area A1, and area A2 in that order (see FIG. 7). In this embodiment, the stepped portion 900a is provided at the boundary between the regions A1 and A2 in the first current path portion Ra, and the stepped portion 900b is provided at the boundary between the regions A3 and A1 in the third current path portion Rc. is provided. In the present embodiment, the stepped portion 900a is provided on a substantially circular arc with the center point of the ceramics member 10 as a base point as viewed in the Z-axis direction and touching the nearest connection portion 821b at a point far from the first power supply portion 812. . In addition, the stepped portion 900b is provided on a substantially circular arc with the center point of the ceramic member 10 as a base point and in contact with the intermediate connection portion 821a at a point far from the first feeding portion 812 as viewed in the Z-axis direction.

A-4. Current flow at first driver electrode 60x:
As described above, in this embodiment, the first heater electrode 500a, the second heater electrode 500b, and the third heater electrode 500c are electrically connected to the first driver electrode 60x and the second driver electrode 60y. connected in parallel to In such a case, as shown in FIG. 7, the amount of current flowing through the first driver electrode 60x is the first V through the first heater-side via 721c in the region A3 of the third current path portion Rc. current I3, which is the amount of current flowing from the heater pad portion 521c. In the region A1 of the first current path portion Ra, the current amount is I1+I3, which is the sum of the current I1 flowing from the first heater pad portion 521a through the first heater-side via 721a and the current I3. In the region A2 of the second current path portion Rb, the current amount is I1+I2+I3, which is the sum of the current I2 flowing from the first heater pad portion 521c through the first heater-side via 721b and the current I1+I3. As described above, the amount of current flowing through the area A1 of the first current path portion Ra is larger than that of the area A3 of the third current path portion Rc, and the amount of current flowing through the second current path portion Rb is It is larger than the area A1 of the first current path portion Ra. In the present embodiment, the thickness of the first driver electrode 60x is increased as the amount of flowing current increases. That is, the thickness Ta of the cross section Xa in the region A1 of the first current path portion Ra is thicker than the thickness Tc of the cross section Xc in the region A3 of the third current path portion Rc. The thickness Tb of Xb is larger than the thickness Ta of the cross section Xa in the region A1 of the first current path portion Ra. By adopting such a configuration, it is possible to reduce the electrical resistance in the portion where the amount of current is large, and to suppress the portion from becoming a high-temperature temperature singular point. Further, in the present embodiment, a step portion 900a is provided between the overlapping portion Rab and the portion other than the overlapping portion Rab in the first current path portion Ra, and in the third current path portion Rc A stepped portion 900b is provided between the overlapping portion Rac and a portion other than the overlapping portion Rac. That is, the thickness Tc is uniform in the region A3 of the third current path portion Rc in which the amount of current flowing is the current I3, and the thickness Tc is uniform in the region A1 of the first current path portion Ra in which the amount of current flowing is the current I1+I3. The thickness is Ta, and the thickness is uniformly Tb in the second current path portion Rb where the amount of current flowing is current I1+I2+I3. With such a configuration, the thickness of the first driver electrode 60x is uniformly the same in the portion where the amount of flowing current is the same. The temperature unevenness in the second current path portion Rb and in the region A3 of the third current path portion Rc can be alleviated.

A-5. Manufacturing method of electrostatic chuck 100:
Next, a method for manufacturing the electrostatic chuck 100 according to this embodiment will be described. First, a plate-like ceramic molded body having a conductive material layer disposed therein is produced. A ceramic molded body can be produced by, for example, a known sheet lamination method or press molding method.

An example of a method for producing a ceramic compact by the sheet lamination method is as follows. First, an alumina raw material, a butyral resin, a plasticizer, and a solvent are mixed, and the resulting mixture is formed into a sheet by a doctor blade method to produce a plurality of ceramic green sheets. In addition, necessary processes such as forming through-holes, filling via ink, and applying electrode ink for forming the chuck electrode 40, the heater electrode layer 50, and the driver electrode 60 are performed on a predetermined ceramic green sheet. conduct. The portion to which the electrode ink is applied becomes the conductive material layer. As the ink for vias and the ink for electrodes, for example, a metallized ink is used which is a slurry obtained by mixing a conductive material such as tungsten or molybdenum, an alumina raw material, an Ethocel (registered trademark) resin, and a solvent. Thereafter, a plurality of ceramic green sheets are laminated, thermocompressed, and processed into a predetermined size to obtain a ceramic compact.

An example of a detailed manufacturing method of the first driver electrode 60x is as follows. When applying the electrode ink for forming the first driver electrodes 60x, first, the electrode ink is applied with a thickness Tc over the entire region where the first driver electrodes 60x are to be formed. Next, the electrode ink is applied to a thickness Tc over the entire region closer to the first power supply portion 812 than the stepped portion 900b when viewed in the Z-axis direction so that the overlapping portion Rac has a thickness Ta. Next, the electrode ink is applied to a thickness Tc over the entire region closer to the first power feeding portion 812 than the stepped portion 900a as viewed in the Z-axis direction so that the overlapping portion Rab has a thickness Tb. By manufacturing the first driver electrode 60x in this way, the thickness Ta at the cross section Xa is the sum of the thickness Tc at the cross section Xc and the thickness Tc at the cross section Xc, and the thickness Tb at the cross section Xb is The thickness is obtained by adding the thickness Tc of the cross section Xc to the thickness Ta of Xa.

After degreasing the obtained ceramic compact in nitrogen, it is sintered under normal pressure at a predetermined temperature (for example, 1500 to 1600° C.) in a humidified hydrogen/nitrogen atmosphere to produce a plate-shaped ceramic sintered body.

Next, the ceramic member 10 and the base member 20 are joined via the joining portion 30 . Specifically, in addition to the ceramic member 10, a base member 20 and a resin-based adhesive (not shown) are prepared. The base member 20 is made of, for example, an aluminum alloy. The adhesive is, for example, a silicone adhesive. An adhesive is placed between the ceramic member 10 and the base member 20 and heated while being pressurized in a vacuum. As a result, the adhesive is cured to form the joint portion 30 , and the ceramic member 10 and the base member 20 are bonded together by the joint portion 30 . After that, post-processing (polishing of outer circumference, formation of terminals, etc.) is performed as necessary. By the manufacturing method described above, the electrostatic chuck 100 having the configuration described above is manufactured.

A-6. Effect of this embodiment:
As described above, the electrostatic chuck 100 of the present embodiment includes the ceramic member 10 having the substantially planar attraction surface S1 substantially perpendicular to the Z-axis direction, and the object ( For example, a holding device for holding a wafer W). The electrostatic chuck 100 includes a linear first heater electrode 500a, a second heater electrode 500b and a third heater electrode 500c arranged inside the ceramic member 10, a first power supply terminal 741 and a second heater electrode 500c. and a power supply terminal 742 . Also, the electrostatic chuck 100 is arranged inside the ceramic member 10, and the first heater pad portion 521a, which is one end of the first heater electrode 500a, and one end of the second heater electrode 500b A first heater pad portion 521b and a first driver electrode 60x electrically connected to a first power supply terminal 741 are provided. In addition, in the electrostatic chuck 100 of the present embodiment, the first driver electrode 60x includes a first power supply portion 812 electrically connected to the first power supply terminal 741 and one of the first heater electrodes 500a. An intermediate connection portion 821a electrically connected to the first heater pad portion 521a, which is an end portion, is located between the first power supply portion 812 and the intermediate connection portion 821a, and is connected to one side of the second heater electrode 500b. and a nearest connection portion 821b electrically connected to the first heater pad portion 521b, which is the end of the heater pad portion 821b. Furthermore, in the electrostatic chuck 100 of the present embodiment, the second current path portion Rb has the overlapping portion Rab, and the area of the cross section Xb of the overlapping portion Ra is It is larger than the area of the cross section Xa of the first current path portion Ra. Since the electrostatic chuck 100 of the present embodiment has such a configuration, as described below, the electrical resistance in the overlapping portion of the second current path portion, which is the portion where the amount of flowing current is large, is reduced. It is possible to suppress the occurrence of a high-temperature temperature singularity.

In such a configuration, the amount of current (current I1+I2) flowing through the overlapping portion Rab is greater than the amount of current (current I1) flowing through the region A1 in the first current path portion Ra, and the first driver electrode 60x , the overlapping portion Rab tends to be a high-temperature temperature singularity.

However, as described above, in the electrostatic chuck 100 of the present embodiment, the area of the cross section Xb of the overlapping portion Rab is the cross section of the first current path portion Ra in the region A1 of the first current path portion Ra. larger than the area of Xa. As a result, the electrical resistance in the overlapping portion Rab, which is a portion through which a large amount of current flows, can be reduced, and the occurrence of a high-temperature temperature singularity can be suppressed.

In addition, in the electrostatic chuck 100 of the present embodiment, the thickness Tb of the cross section Xb of the overlapping portion Rab in the Z-axis direction is thicker than the thickness Ta of the cross section Xa of the first current path portion Ra. Since the electrostatic chuck 100 of the present embodiment has such a configuration, in the overlapping portion Rab of the first driver electrode 60x, which tends to become a high-temperature temperature singular point due to a large amount of flowing current, Electric resistance can be reduced, and the occurrence of a high-temperature temperature singularity can be suppressed.

Further, in the electrostatic chuck 100 of the present embodiment, a stepped portion 900a is provided between the overlapping portion Rab and a portion other than the overlapping portion Rab in the first current path portion Ra. Since the electrostatic chuck 100 of the present embodiment has such a configuration, the temperature unevenness in the overlapping portion Rab in the first current path portion Ra and the temperature in the portions other than the overlapping portion Rab are reduced. temperature unevenness can be alleviated.

In addition, the electrostatic chuck 100 of the present embodiment further includes a linear third heater electrode 500c arranged inside the ceramic member 10 . In addition, in the electrostatic chuck 100 of the present embodiment, the first driver electrode 60x is located on the side opposite to the nearest connection portion 821b with respect to the intermediate connection portion 821a, and is positioned at one end of the third heater electrode 500c. It includes a farthest connection portion 821c electrically connected to a certain first heater pad portion 521c, and a third current path portion Rc between the first power feeding portion 812 and the farthest connection portion 821c. . Furthermore, in the electrostatic chuck 100 of the present embodiment, the third current path portion Rc has an overlapping portion Rac that overlaps the first current path portion Ra when viewed in the Z-axis direction. Among them, the area of the cross section Xa of the overlapping portion Rac in the region A1 is larger than the area of the cross section Xc of the third current path portion Rc in the region A3. In the electrostatic chuck 100 of the present embodiment, the thickness Ta of the cross section Xa of the overlapping portion Rac is thicker than the thickness Tc of the cross section Xc of the third current path portion Rc in the Z-axis direction. Since the electrostatic chuck 100 of the present embodiment has such a configuration, as described below, the electrical resistance in the overlapping portion Rac, which is a portion through which a large amount of current flows, is reduced, and in turn, the high temperature temperature singularity can be suppressed.

In such a configuration, the amount of current (current I1+I3) flowing through the region A1 between the intermediate connection portion 821a and the nearest connection portion 821b in the overlapping portion Rac of the third current path portion Rc is the third current path portion Rc. The portion Rc is larger than the amount of current (current I3) flowing through the region A3 between the intermediate connection portion 821a and the farthest connection portion 821c, and the overlapping portion Rac of the third current path portion Rc in the first driver electrode 60x. A region A1 between the intermediate connection portion 821a and the nearest connection portion 821b in the third current path portion Rc has a higher temperature than the region A3 between the intermediate connection portion 821a and the farthest connection portion 821c. easy to become.

However, as described above, in the electrostatic chuck 100 of the present embodiment, the intermediate connection portion in the region A1 between the intermediate connection portion 821a and the nearest connection portion 821b in the overlapping portion Rac of the third current path portion Rc The area of the cross section Xc of the overlapping portion Rac of the third current path portion Rc substantially orthogonal to the direction from 821a toward the first power supply portion 812 is the farthest from the intermediate connection portion 821a in the third current path portion Rc. By increasing the area of the cross section Xc of the third current path portion Rc substantially perpendicular to the direction from the farthest connection portion 821c to the first feeding portion 812 in the region A3 between the connection portions 821c, the flow of current is reduced. Reduce the electrical resistance in the region A1 between the intermediate connection portion 821a and the nearest connection portion 821b in the overlapping portion Rac of the third current path portion Rc, which is a portion with a large amount of current, and eventually generate a high-temperature temperature singularity. can be suppressed.

In the electrostatic chuck 100 of the present embodiment, the thickness Ta of the cross section Xa of the overlapping portion Rac of the third current path portion Rc in the Z-axis direction is made thicker than the thickness Tc of the cross section Xc of the third current path portion Rc. As a result, the area of Xa is made larger than the area of Xc. Therefore, in the electrostatic chuck 100 of the present embodiment, electricity is generated in the overlapping portion Rac of the third current path portion Rc in the first driver electrode 60x, which is likely to become a high-temperature singular point due to the large amount of current flowing therethrough. The resistance can be reduced, and the occurrence of a high-temperature temperature singularity can be suppressed.

B. Variant:
The technology disclosed in this specification is not limited to the above-described embodiments, and can be modified in various forms without departing from the scope of the invention. For example, the following modifications are possible.

The configuration of the electrostatic chuck 100 in the above embodiment is merely an example, and various modifications are possible. For example, in the electrostatic chuck 100 of the above embodiment, the first feeding portion 812, the intermediate connection portion 821a, the closest connection portion 821b, and the farthest connection portion 821c are positioned on the same straight line when viewed in the Z-axis direction. , at least one of which may not be located on the same straight line. A specific description will be given with reference to FIGS. 8 and 9. FIG. FIG. 8 is an explanatory diagram showing the positional relationship between the first heater-side via 721 and the first power supply-side via 711 in the first driver electrode 60x of the electrostatic chuck 100 of the modified example. FIG. 9 is an explanatory diagram showing a current path portion in the first driver electrode 60x of the electrostatic chuck 100 of the modified example. In FIG. 8, the nearest connection portion 821B is not positioned on the straight line formed by the first power feeding portion 812 and the intermediate connection portion 821A when viewed in the Z-axis direction. In this case, the first current path portion RA and the second current path portion RB are defined as described above, as are the first current path portion Ra and the second current path portion Rb, respectively. That is, the first current path portion RA is defined based on the intermediate connection portion 821A and the first feeding portion 812 (see A in FIG. 9), and the second current path portion RB is defined based on the nearest connection portion 821B and the first power supply portion 812. 1 feed portion 812 (see FIG. 9B). A portion of the first current path portion RA that overlaps the second current path portion RB when viewed in the Z-axis direction is an overlapping portion RAB between the first current path portion RA and the second current path portion RB (see FIG. 9C). In this case, in the first driver electrode 60x of this example, the area of the cross section XB of the overlapping portion RAB of the second current path portion RB is the first current in the region A1 of the first current path portion RA. larger than the area of the cross section XA of the route portion RA. The cross section XB of the overlapping portion RAB is a cross section substantially perpendicular to the direction from the nearest connecting portion 821B toward the first feeding portion 812 in the overlapping portion RAB. The cross section XA of the first current path portion RA refers to the area A1 between the intermediate connection portion 821A and the nearest connection portion 821B in the first current path portion RA, from the intermediate connection portion 821A to the first feeding portion 812. is a cross section substantially orthogonal to the direction toward . In this example, area A1 is the area between middle connecting portion 821A and nearest connecting portion 821B. Specifically, the area A1 is two straight lines perpendicular to the virtual straight line connecting the center point of the intermediate connection portion 821A and the center point of the closest connection portion 821B, and is the intermediate connection portion 821A (first feeding portion A tangent line that is in contact with the furthest point from the closest connection portion 821B among the points on the circumference of the intermediate connection portion 821A that is farther from the first feeding portion 812, and the closest connection portion 821B (the distance from the first feeding portion 812 is It is the area bounded by the tangent line that is tangent to the point on the circumference of the closer closest connecting portion 821B) that is closest to the intermediate connecting portion 821A. Further, in this example, the stepped portion 900C is provided in a stepped manner downward in the Z-axis direction. Further, the stepped portion 900C is provided on a substantially circular arc with the center point of the ceramics member 10 as a base point as viewed in the Z-axis direction and contacting the nearest connection portion 821B at a point far from the first feeding portion 812 .

Although the stepped portions 900a, 900b, and 900C are provided stepwise in the above embodiment, they may be provided in a slanted shape at the boundaries of the first driver electrodes 60x having different thicknesses.

At least one of the stepped portions 900a, 900b, and 900C may be provided in a portion described below. Specifically, the step portion 900a is provided at least at the boundary between the overlapping portion Rab and the portion other than the overlapping portion Rab in the first current path portion Ra of the first driver electrode 60x as viewed in the Z-axis direction. It is good if it is For example, the stepped portion 900a can be provided downward in the Z-axis direction at the outer edge of the overlapping portion Rab in the first current path portion Ra as viewed in the Z-axis direction. Since the stepped portion 900b is similar to the stepped portion 900a, the description thereof is omitted. Moreover, the step portion 900C is provided at least in the boundary portion between the overlapping portion RAB and the portion other than the overlapping portion RAB as viewed in the Z-axis direction in the first current path portion RA of the first driver electrode 60x. Just do it. For example, the stepped portion 900C can be provided downward in the Z-axis direction at a portion of the first current path portion RA where the outer edge of the overlapping portion RAB overlaps when viewed in the Z-axis direction.

At least one of the first feed portion 812, the intermediate connection portion 821a, the nearest connection portion 821b, and the farthest connection portion 821c may be the portions described below. Specifically, the first feeding portion 812 will be described. The first power feeding portion 812 may be a portion surrounded by the outer circumference of the first electrode pad 731 with the smallest circle that includes all of the first power feeding side vias 711 when viewed in the Z-axis direction. Since the intermediate connection portion 821a, the nearest connection portion 821b, and the farthest connection portion 821c are also the same as the first feeding portion 812, description thereof will be omitted.

In the above embodiment, the first feed portion 812, the intermediate connection portion 821a, the closest connection portion 821b, and the farthest connection portion 821c are substantially circular with the same diameter. It may be substantially circular with different diameters. In this case, the current path portion can be defined as follows. Specifically, the case where the intermediate connection portion 821a has a substantially circular shape with a diameter larger than that of the first feeding portion 812 will be described. First, a first line that is parallel to a straight line passing through the center point of the intermediate connection portion 821a and the center point of the first feed portion 812 and has the smaller diameter of the intermediate connection portion 821a and the first feed portion 812. Two tangent lines TL are defined that are in contact with the circumference of the feeding portion 812 . A portion surrounded by the two tangent lines TL, the outer circumference of the intermediate connection portion 821a, and the outer circumference of the first power supply portion 812, is formed by the portion including the intermediate connection portion 821a and the first power supply portion 812. can be defined as a first current path portion Ra.

In the above embodiment, the first heater electrode 500a, the second heater electrode 500b and the third heater electrode 500c are electrically connected in parallel with the first driver electrode 60x and the second driver electrode 60y. Although connected, the number of heater electrodes is not limited to three, and may be two, or four or more.

Further, in the above embodiment, the vias electrically connected to the first electrode pad 731, the first heater pad portion 521a, the first heater pad portion 521b, and the first heater pad portion 521c are respectively four. Although the via group is composed of vias, the number of vias constituting the via group is not limited to four. Also, the number of vias is not limited to plural, and may be single.

In the above embodiment, the second driver electrode 60y paired with the first driver electrode 60x to which the heater electrode layer 50 is connected in parallel may also have the same configuration as the first driver electrode 60x. . By adopting such a configuration, it is possible to reduce the electrical resistance of the second driver electrode 60y also in the portion where the amount of current flowing is large, thereby suppressing the occurrence of a high-temperature temperature singular point.

Further, in the above-described embodiment, a monopolar system in which one chuck electrode 40 is provided inside the ceramic member 10 is adopted, but a bipolar system in which a pair of chuck electrodes 40 are provided inside the ceramic member 10 is adopted. may be adopted. Further, the materials forming each member in the electrostatic chuck 100 of the above-described embodiment are merely examples, and each member may be formed of another material.

Further, the present invention is not limited to the electrostatic chuck 100 which includes the ceramic member 10 and the base member 20 and holds the wafer W using electrostatic attraction, but also includes a ceramic member and holds an object on the surface of the ceramic member. It is also applicable to other holding devices (for example, heater devices such as CVD heaters, vacuum chucks, etc.).

Reference Signs List 10: Ceramic member 12: Recess 20: Base member 21: Coolant channel 22: Through hole 30: Joint 32: Through hole 40: Chuck electrode 50: Heater electrode layer 60: Driver electrode 60x: First driver electrode 60y: Second driver electrode 100: electrostatic chuck 110: first terminal hole 120: second terminal hole 500: heater electrode 500a: first heater electrode 500b: second heater electrode 500c: third heater Electrode 510: heater line portion 521: first heater pad portion 521a: first heater pad portion 521b: first heater pad portion 521c: first heater pad portion 522: second heater pad portion 711: first heater pad portion 712: second power supply side via 721: first heater side via 721a: first heater side via 721b: first heater side via 721c: first heater side via 722: second heater side via Side via 722a: Second heater side via 731: First electrode pad 732: Second electrode pad 741: First power supply terminal 742: Second power supply terminal 812: First power supply part 821A: Intermediate connection part 821B: Closest connection portion 821a: First connection portion (intermediate connection portion) 821b: Second connection portion (closest connection portion) 821c: Third connection portion (farthest connection portion) 900C: Stepped portion 900a: Stepped portion 900b: step portion Ra: first current path portion Rab: overlapping portion Rac: overlapping portion Rb: second current path portion Rc: third current path portion RA: first current path portion RAB: overlapping portion RB: Second current path portion

Claims (5)

a ceramic member having a substantially planar first surface substantially perpendicular to the first direction;
a linear first heater electrode and a linear second heater electrode arranged inside the ceramic member;
a first power supply terminal;
a driver electrode disposed inside the ceramic member and electrically connected to one end of the first heater electrode, one end of the second heater electrode, and the first power supply terminal; ,
A holding device for holding an object on the first surface of the ceramic member,
The driver electrodes are
a first feeding portion electrically connected to the first feeding terminal;
a first connection portion electrically connected to the one end of the first heater electrode;
a second connection portion located between the first power supply portion and the first connection portion and electrically connected to the one end of the second heater electrode;
a first current path portion between the first feeding portion and the first connecting portion;
a second current path portion between the first feeding portion and the second connecting portion;
The second current path portion has an overlapping portion that overlaps the first current path portion when viewed in the first direction,
In the overlapping portion of the second current path portion, the cross-sectional area of the overlapping portion of the second current path portion that is substantially orthogonal to the direction from the second connecting portion to the first feeding portion is in a region between the first connection portion and the second connection portion of the first current path portion, substantially orthogonal to a direction from the first connection portion to the first power supply portion; larger than the cross-sectional area of the first current path portion,
A holding device characterized by: A holding device according to claim 1, wherein
In the first direction, the cross-sectional thickness of the overlapping portion of the second current path portion is thicker than the cross-sectional thickness of the first current path portion;
A holding device characterized by: A holding device according to claim 2, wherein
In the first current path portion, a stepped portion is provided between the overlapping portion of the second current path portion and a portion other than the overlapping portion of the second current path portion,
A holding device characterized by: In the holding device according to any one of claims 1 to 3,
further comprising a linear third heater electrode arranged inside the ceramic member,
The driver electrodes are
a third connection portion located on the opposite side of the second connection portion with respect to the first connection portion and electrically connected to one end of the third heater electrode;
a third current path portion between the first feeding portion and the third connecting portion;
The third current path portion has an overlapping portion that overlaps the first current path portion when viewed in the first direction,
In the overlapping portion of the third current path portion, in a region between the first connecting portion and the second connecting portion, in a direction from the first connecting portion toward the first feeding portion The cross-sectional area of the overlapping portion of the third current path portion that is substantially perpendicular to the third current path portion is the area between the first connection portion and the third connection portion of the third current path portion. larger than the cross-sectional area of the third current path portion substantially perpendicular to the direction from the third connection portion to the first power supply portion;
A holding device characterized by: a ceramic member having a substantially planar first surface substantially perpendicular to the first direction;
a linear first heater electrode and a linear second heater electrode arranged inside the ceramic member;
a first power supply terminal and a second power supply terminal;
a driver electrode disposed inside the ceramic member and electrically connected to one end of the first heater electrode, one end of the second heater electrode, and the first power supply terminal; ,
A holding device for holding an object on the first surface of the ceramic member,
The driver electrodes are
a first feeding portion electrically connected to the first feeding terminal;
a first connection portion electrically connected to the one end of the first heater electrode;
a second connection portion located between the first power supply portion and the first connection portion and electrically connected to the one end of the second heater electrode;
a first current path portion between the first feeding portion and the first connecting portion;
a second current path portion between the first feeding portion and the second connecting portion;
The second current path portion has an overlapping portion that overlaps the first current path portion when viewed in the first direction,
The thickness of the cross section of the overlapping portion of the second current path portion substantially perpendicular to the direction from the second connecting portion to the first power feeding portion in the overlapping portion of the second current path portion is in a region between the first connection portion and the second connection portion of the first current path portion, substantially orthogonal to a direction from the first connection portion to the first power supply portion; thicker than the cross-sectional thickness of the first current path portion;
A holding device characterized by:

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